In the univariate analysis, persistent/recurrent anemia was found to be associated with CD diagnosis [OR 1.59 (1.16–2.19), p = 0.0044], median disease duration [1.03 (1.01–1.05), p = 0.0100], penetrating or stricturing CD [2.07 (1.40–3.07), p = 0.0003], presence of EIMs [1.82 (1.33–2.49), p = 0.0002] use of anti-TNF [1.53 (1.11–2.12), p = 0.0090], IBD related hospitalizations [2.39 (1.56–3.66), p = 0.0001] and IBD related surgeries [2.15 (1.43–3.23), p = 0.0002] (Table 4). This evidence concerns the gene TNF and anemia (phenotype).